Problem: Express your answer as a mixed number simplified to lowest terms. $15\dfrac{3}{5}+4\dfrac{1}{5} = {?}$
Separate the whole numbers from the fractional parts: $= {15} + {\dfrac{3}{5}} + {4} + {\dfrac{1}{5}}$ Bring the whole numbers together and the fractions together: $= {15} + {4} + {\dfrac{3}{5}} + {\dfrac{1}{5}}$ Add the whole numbers: $=19 + {\dfrac{3}{5}} + {\dfrac{1}{5}}$ Add the fractions: $= 19+\dfrac{4}{5}$ Combine the whole and fractional parts into a mixed number: $= 19\dfrac{4}{5}$